Retinal implants are being pursued by some 18 groups around the world, have been tested acutely by at least 5, and are being evaluated clinically by at least one consortium currently and by another 3 within the next year. Second Sight Medical Products (SSMP) has been developing tools to train and test implant recipients in its Argus II trial, mostly in response to its own need and requirements by the FDA to quantify and document prosthesis function and patient performance. Some procedures were developed within SSMP, while others build on existing tests and training materials developed in low vision rehabilitation, in visual prosthesis trials, in pre-clinical visual prosthesis studies, and in prosthetic vision simulations. Yet, while building blocks of a future rehab curriculum do exist, no integrated approach to prosthetic low vision rehabilitation has been formulated. The immediate goal of the proposed program is to integrate, refine, and create tools for assessment and rehabilitation of ultra-low vision into a program that will provide research and clinical teams in the area of electronic visual prosthetics with the means to train, track, and evaluate implant patients, and collect the outcomes required to demonstrate functional effectiveness. The resulting ensemble of training and assessment tools, along with manuals and on-line course materials, will form a Prosthetic Low Vision Rehabilitation (PLoVR) curriculum. Specifically, we propose to 1. Expand the scale of visual tasks and abilities used in low vision rehabilitation towards ultra-low vision. A population of patients with extremely limited vision will create a bank of activities, and be asked to rank these according to difficulty; a logit scale of item measures will be created through Rasch analysis. 2. Design and refine practice and assessment tools for minimally sighted individuals. We will create, and expand on, tools that stimulate and assess the use of vision (visual information gathering and of visually guided performance) and develop scoring systems and composite outcomes. 3. Evaluate the use of practice and assessment tools in patients with severe and profound vision loss. A group of ultra-low vision subjects will perform the tasks developed under Aim 2, for multiple parameter settings; Rasch analysis will be used to assign a difficulty score to each task and parameter setting.. 4. Validate the tools and scoring system in experienced and new retinal implant recipients. A group of 10 retinal implant wearers will practice and perform the same tasks; Rasch analysis will be used to examine potential differences between the two subject groups 5. Disseminate the PLoVR core curriculum: surveys, performance tasks, instructions and documentation We will create instruction manuals, an on-line course, and a user group for future PLoVR curriculum users. The PLoVR curriculum will be made available to research consortia pursuing treatment modalities for advanced eye disease, as a uniform set of standards to demonstrate clinical and functional effectiveness.